/*
 * Copyright (C) 2011 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.magiclen.gson.internal.bind;

import org.magiclen.gson.Gson;
import org.magiclen.gson.JsonSyntaxException;
import org.magiclen.gson.TypeAdapter;
import org.magiclen.gson.TypeAdapterFactory;
import org.magiclen.gson.reflect.TypeToken;
import org.magiclen.gson.stream.JsonReader;
import org.magiclen.gson.stream.JsonToken;
import org.magiclen.gson.stream.JsonWriter;
import java.io.IOException;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;

/**
 * Adapter for java.sql.Date. Although this class appears stateless, it is not.
 * DateFormat captures its time zone and locale when it is created, which gives
 * this class state. DateFormat isn't thread safe either, so this class has to
 * synchronize its read and write methods.
 */
public final class SqlDateTypeAdapter extends TypeAdapter<java.sql.Date> {

    public static final TypeAdapterFactory FACTORY = new TypeAdapterFactory() {
        @SuppressWarnings("unchecked") // we use a runtime check to make sure the 'T's equal
        @Override
        public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
            return typeToken.getRawType() == java.sql.Date.class
                    ? (TypeAdapter<T>) new SqlDateTypeAdapter() : null;
        }
    };

    private final DateFormat format = new SimpleDateFormat("MMM d, yyyy");

    @Override
    public synchronized java.sql.Date read(JsonReader in) throws IOException {
        if (in.peek() == JsonToken.NULL) {
            in.nextNull();
            return null;
        }
        try {
            final long utilDate = format.parse(in.nextString()).getTime();
            return new java.sql.Date(utilDate);
        } catch (ParseException e) {
            throw new JsonSyntaxException(e);
        }
    }

    @Override
    public synchronized void write(JsonWriter out, java.sql.Date value) throws IOException {
        out.value(value == null ? null : format.format(value));
    }
}
